Means for coating by spraying



March 3l, 1936. A, KRAUTZBERGER Re. 19,907

`mms FoRcoATINe BY sPnAYINe Original Filed llay 10, 1930 lRessued Mar. 31, 1936 Albert Krautzberger, Holzhausemf near Leipzig, Germany, assignor to Royce A. Ruess, Washington, D. C.

original No. 1,939,6M, dated December 12, 1933.

Serial No. 451,376, May 10, 1930.

Application for reissue February' 25, 1935, Serial No. 8,307. In Germany August 8. 1929 14 Claims. (Cl. 299-1401) A This invention relates to apparatus for spraying on paint and the like.

In one class of paint spraying apparatus, hereinafter referred to as the compressed air system. the spraying is effected by compressed air which atomizes the mass to be sprayed, which may be A drawn into the spraying nozzle by means of the compressed air -or may be supplied thereto by' means of a pump or by gravity, in which latter g case considerable economy in operation is obtained. In all cases, however, the expanding compressed air disperses the mass in the form of l a mist or the like, except in the case ofpressure fed apparatus, when-fthe mass is fed at a pressure which is excessive as compared with that of the I compressed air, in which` the mass is expelled in i the` form of a more or less compact solid jet, which is useful for cleaning and other purposes. f

VSpraying pistols or guns have been proposed comprising a body or handle portion and a spray- 4ving head detachably secured thereto and having la spraying nozzle for the material to be sprayed, Ia supply channel for conveying the said material Qto the nozzle, an air channel and an air discharge l,nozzle which co-operates with the spraying nozlzle, the exit of the material to be sprayed from the spraying nozzle being controlled by means o f a valve spindle passing rearwardly through the spraying head and operated by a control member mounted on the handle or body portion, which member is also arranged to control the supply of' compressed air to the air discharge nozzle. In this construction, the spraying nozzle is screwed into the spraying head. which is mounted on the body or handle portion by inserting into a tubular portion of the latter a rearwardly extending tubular' member through-which the valve spindle is passed, the said tubular member being held in position by means of a clamping nut on a screw pin iixed on the tubular member and passing through a slot in the tubular portion of the body or handle. while the supply of air to the air discharge nozzle Ais controlled by` a second valve spindle passed through a second vrearwardly exbending tubular member on the spraying head.

According to I the present invention. thel air supply to the air discharge nozzle is controlled by neans' of an` air valve through which the c'om- Dressedair is supplied to the spraying head and which is arranged on the handle or body portion rf the pistol oil'set with respect to the valve spinile. 'Ille movement of the valve spindle, which s effected by hand, pneumatically and mechancally,is controlled by a controlling piston slid-- ble in spindle seating direction preferably by a spring,

and in the opposite direction both manually and pneumatically. Preferably adjusting means is provided on the body of the pistol for limiting the displacement of the piston.

The invention is illustrated by way of exampley inthe accompanying drawing..in which Figure l shows a hand-operated spraying pistol in longitudinal section. Figure 2 -shows the spraying head slightly modined in longitudinal section. Figure 3 shows the spraying nozzle of Fig. 2,in elevation and Figure ishows the centering h'ead as seen from the front in Fig. 2.

Referring to the drawing, 8 is a compressed is pressed against its seat. in the chamber by means oi' a spring 33. The air valve 8 is raised from its seatl when required, against the force of the spring 33- by means of a lever 2l which engages the end of the valve spindle at a point 54 near the pivot 53 of the lever.- Below the valve chamber 58 is provided a rotatable sleeve 58 which is closed at both ends and has alateral opening 51 nearits forward end, which opening is adapted to register with an opening 4I in the valve chamber 58 whenthe sleeve 58 is turned into the appropriate position. By this means,

compressed air can be admitted. to the sleeve piston, an aperture 69 in this end oi the hollow spindle I8 permitting air to pass into its interior from the sleeve 56. The forward end of the spindle I8 is guided in theV spraying head A and serves as control valve for shutting ofi the supply of paint or othermaterial to be sprayed .at II, while compressed air can be supplied through its hollow interior to the centr'e of the jet issuing from the spraying head.' The spindle I8 is displaced axially to permit the exit of paint or other ma- -terial'from the spraying head by means of a projection 3| which is engaged by a driving member 52 ilxed to the lever 24, so that the spindle I8 and valve 9 can both be actuated by it. By this arrangement, the spring 82 of the paint supply control valve constituted by the spindle` I8 can be made suilciently large to ensure the spindle having a sufiicient axial displacement, while the position of the air valve spindle above. the paint supply control spindle and the placing of both spindles behind the lever 24 enables the most satisfactory leverage and distribution of weight- -tance required for allowing the spraying head A to be tted to the body B. By this arrangement the lever 24, when moved rearwardly to open the valves, has an initial lost movement relative to the projection 2 i, so that the air valve 9 is opened slightly in advance oi' the material valve I8. This arrangement oi' the parts also enables the spindle Il to be guided so as to work easily and still allow no paint or solvent to escape in spite of the considerable spraying pressures, the spindle Il being guided in a centering collar 22 and packed by a relatively long spindle packing i9 in the spraying head, while the favourable leverage of the lever 24 enables the spindle to be axially dis` placed with very little force. -The closing end of the spindle IB is also enabled to seat itself properly on its seating in the spraying head.

The spraying head A comprises a tubular member 2 3 to which the material to be sprayed is supplied through an inlet t0, the. centering collar4 22 forming a. rearward extension of said tubular member. The spraying head is connected to the body part B in properalignment by means of the centering collar l22 and a imion nut I3 which tits over the centering collar and is screwed on to a suitable threaded part of the part B. 0n

vthe forward threaded end 41 of the tubular mem- .berZIissecuredanozzle'lwhichhasacollar 25 which is pressed against the threaded end ofthe member 23 bymeansotashoulderon a centering head I which is screwed on to the threaded end 4'| (Fig. 1l centering head l is construcied'so as to form an air nozzle surrounding the nozzle 1 and is provided with lateral :n1-et openings so. The

spraying head is provided with a cover 8| having oblique apertures 82 tor enabling air to flow roundthevoutside -oi the mass being sprayed to a point in front of the iaee of the spraying head.

The passage ot'air ip the apertures l2 is controlledby'meansofslots 62 inapart ofthe air nome l, the quantity of air passing through the m68 being varied by turning lthe cover Il soastochangethepositions ottheapertureswithrespeettotheslotsll.

In order to 'prevent rotation ot the air nomic t whenthecoverti is turned, in the constructional formo! 'sprayingheadshown in Figures Htheairnomieisnotscrewedtotheendoi ithetube butissecuredtheretobymeansofa 75 premrooithecirculatingmassrlnlordertobe moreveasily operated (with the thumb and ilrst linger ot the lei't hand) the gland 39 is grooved and provides a metallic guide for the regulating spindle i8. Any differences in direction which may occur in consequence of wear at this part or anywhereelse are compensated by the piston which slides in the end tube' 56. On the tube 56 isl screwed the stroke regulating cap it. By means of the latter the stroke of the adjusting piston 55 and that'of the spindle i8 and consequently the distance to which the mass can be thrown and the thickness of the jet are determined. The cap I6 is forl this purpose provided with an internal axially extending rod |55 forming a stroke limiting stop againstwhich the inside end wall oi the piston strikes onbeing moved rearwardly by the lever 24 and spindle i0, the

4 tube 8 under the control of a supply control valve i1 to the valve chamber 58 and from there nows -through the part B to the spraying head A, and

when required, also passes through the aperturev 4 I Ato the hollow spindle it. The valve i1 determines the air pressure and the quantity ot alr lsuppliedgwhile the air valve and piston ot the rotary sleeve 65 determine the kind of jet and its thicknem.

It is apparent that when the .valve 9 is openl the air under pressure, which is admitted to sleeve I6 in advance oi the piston 55. will counteract..to some extent at least, the pressure of the spring -22 and thus leasen, to such extent. the pressure required to be applied to the hand lever 24 to hold the valve spindle i8 open during operation. This teature is important, as it renders the use of the spray-gun less tiring to the operator, particulariyunder prolonged spraying operations, and requires less `pressure to retract the valve i8 than would otherwise be the case, and at the same time .enables the full pressure oi the spring A32 -to be utilized to hold the valve seated whenthegunisnotinuse.v A It is evident that the admission of air to the forward end of the chamber in which the piston 55 works and to the passage through the valve spindle i8 may be regulated by a turning oi' the sleeve It to place the ports 4I and 61 entirely into or out of register orpartially inregister. In this way, the pressure oi the air in the piston chamber. which counteracts the valve spindle closing pressure-ofthe spring I2, can be regulated to suit requirements. Y

What I claim is:

l. A spraying pistol'comprising the combinationwith a body portion and a spraying head detaehably secured thereto and having a spraying`nozzle for the material to be sprayed, a supply channel for conveying said material to said nozzle, an air channel. an air discharge nozzle associated with the-spraying nozzle and a valve spindle for controlling the exit o! the material to be sprayed from the spraying nozzle. said valve spindle being through the spraying head so as to extend rearwardiythereirom, of a rearwardlyextendingtubularxnember on the spraying head through which the valve spindle is passed. said tubular member 'having a centering collar thereon, a screw-threaded part on the body of the pistol adapted to receive said tubularmember and an adJusting nut fitted over said centering collar so as to be rotatable thereon and screwed on said screw-threaded part on the bodyV of thevpistol, a control member for actuating said valve spindle mounted on said body portion, said body portion of the spraying pistol having an air supply conduit in open communication with the air channel in the spraying head and an air valve for controlling the supply of compressed air to said air channel, said air valve arranged in said body portion offset with respect to said valve spindle and having a portion thereof projecting out of the body portion so as to be actuatable bythe said control member for actuating the valve spindle.

2. A spraying pistol comprising the combination with a body portion and a spraying head detachably secured thereto and having a spraying nozzle for the material to be sprayed, a supply channel for conveying said material to said nozzie, an air channel, an air discharge nozzle associated with the spraying nozzle and a valve spindle for controlling the exit of the material to be sprayed from the spraying nozzle, said valve spindie being passed through the spraying head so as to extend rearwardly therefrom, a sleeve in the body oi' the pistolpositioned therein with-its axis offset with respect' to the axisof the valve spindle, said sleeve having an inlet f oradmitting compressed air to its interior and being rotatable from a position with said inlet out of open communication with, the air supply conduit in the body portion of the pistol into a position in open communication therewith, a controlling piston slidable in the body of said sleeve for controlling the-movement of the valve spindle, said valve spindle being hollow and having its rear end passed into the body portion of the pistol so as to engage the controlling piston with the interior of the valve spindle in open communication with the interior of the rotatable sleeve, a control member for actuating said valve spindle mounted on saidbody portion, said body portion of the spraying pistol -having an air supply conduit in open communication with the air channel in the spraying head and an air valve for controlling the supply of compressed air to said air channel, said air valve arranged in said body portion oil'set with respect to said valve spindle and having a portion thereof projecting out of the body portion so as to bel actuatable by the said control member for actuating the valve spindle.

3. In a material discharge' gun, a material valve, means acting on said valve to exert a predetermined closing pressure thereon, means manually operable to open the valve against said closing pressure, and means pneumatically'operable to counteract a portion of the closing pressure of said iirst means.

4. In a spray gun. a material control valve, an air pressure control valve, means acting on the material valve to exert a closing pressure thereon, means manually operable to open the air valve and also the material valve against the pressure of said means, said closing means being automatically operable by air pressure, 'when the air valve is open, fp counteract a portion of the closing pressure of the closing means.

5. In a spray gun, a normally closed air valve and a normally closed material valve for the gun.

. spring pressure means acting cn the material -valve to exert a closing pressure thereon and including a cylinder and piston at the outlet side oi the air valve and in communication with being normally closed, -a spring pressed plunger normally operable to exert a predetermined closing pressure on the materialvalve and pneumatically operable by air pressure when the air valve is opened to partially relieve said closing pressure, and manually operable means to open the air and material valves one in advance of the other.

'7. In a spray gun, normallyclosed controlA valves respectively for the air and material discharge, a plunger exposed to the air discharging pressure at the outlet side ot said valve and having connection with the material valve,

means yieldingly acting on -said plunger to cause' it to exert a predetermined closing pressure on the material valve, said plunger being operated by air pressure, when the air valve is open, to counterbalance a portion of the pressure oi' said yielding means against the plunger, means' manually operable to open rst said air valve and then the material valve, and means for adjusting the tension of said pressure means.

8. In a spray gun, normally closed control va'lves respectively for'the air and material discharging from the gun, a plunger having closing coaction with the material valve, a spring acting against said plunger toexert a predetermined valve-closing pressure thereon, said plunger being exposed at one-side to theair discharging pressure'when the air valve is open and being automatically operable by such air pressure to counteract a portion at least ot the closing pressure of said spring, and means manually operable to open said air and material valves.

9. In a material discharge gun. a material valve, means acting on said valve to exert a predetermined closingpressure thereon, Vmeans manually operable to open the valve against said closing pressure, and means 4rendered operable Vby a predetermined valve opening movement of said manually operable means to counteract a portion of the closing pressure of said rst means.

10. In a material discharge gun, a material valve, means acting on said valve to exert a predetermined closing pressure thereon, means manually operable to open'the valve against said closing pressure, meansoperable to counteract a portion of the closing pressure oi.' said ilrst means, and means actuated by a valve opening movement ot said manually operable means to render said last means active.

11. In a spray gun. a material control valve, pressure means normally exerting a closing pressure on said valve, means operable to open the valve againstsaid closing pressure. and means rendered operable by a predetermined valve opening movement of said operating means to ,counteract a portion of the valve closing pressure of said pressure means.

12. In a spray gun, a spray head having a ma-1 terial discharge passage, a material control .valve tor said passage, means acting on said valve to exert a predetermined closing pressure thereon. means manually operable to open said' valve against said closing pressure, means pneumaticallyoperable to counteract a portion of the closing pressure afraid ilrst means. and means adlinstable to vary the degree of action of said pneumatic means. I

13. In a spray gun, an air cylinder, a piston working in said cylinder. a material control valve in connection with said piston. yielding pressure means for imparting a valve seating movement to said piston, means manually operable to open said valve against said pressure means, means rendered operative by movement o! said manual means to admit air under pressure to said cylinder to act against said piston and counteract to a predetermined extent the valve seating action o t said pressure means. and means (or regulating the air pressure in said cylinder. l

14; In a spray gun, a spray head having air and material Adischarge passages, a valve for closing said material discharge passage, a cylinder.

a spring pressed piston in said cylinder coasting with said valve and .acting to normally hold the valve seated, means manually operable to unseat said valve against the seating spring pressure. means forming an air pressure supply passage i in communication with the air discharge Passage g of the spray head. said supply passage also having communication with said cylinder to admit i air under pressure thereto to counteract a por- I tion ot the valve closing pressure o! said piston. g a valve tor closing said supply e anteriori to its communication and opened by a predeter-g mined movement ot said manual means. andg means for controlling the admission of air presgl sure to said cylinder.

ALBERT KRAUTLBERGER. 

